Cartridge unit having a plurality of supporting portions for supporting a cartridge and a protection cover for protecting a photosensitive drum of the cartridge

ABSTRACT

A cartridge includes a cartridge main body, a protection member, a rib of the cartridge main body, and a pair of guides of the protection member, wherein an upstream-side guide of the guides can guide the rib when the cartridge main body is inserted into a device main body, and terminates the guide after allowing the cartridge main body to be inserted up to a position where the cartridge main body becomes independent of the device main body.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a cartridge detachably attachable to adevice main body, and an image forming apparatus to which the cartridgeis attached/detached.

Description of the Related Art

In image forming apparatuses of Japanese Patent Laid-Open No.2007-240661, there is one in which a protection member can be positionedto a device main body, the protection member cannot be pulled out of thedevice main body during mount of the cartridge, and an engaging portionof the protection member is cancelled after mount of the cartridge andthe protection member can be removed. This system can prevent theprotection member from falling during insertion of the cartridge.

Further, this system employs a configuration in which a guide rail(support portion) is provided in the protection member, and a rib of theprocess cartridge is moved on the guide rail. Therefore, the protectionmember serves as a guide at the time of insertion of the processcartridge, and also prevents the falling.

Meanwhile, downsizing and space saving are desired for the processcartridge and the protection member in terms of downsizing a device mainbody and distribution of the process cartridge. Further, if theprotection member is increased in size, the material is increased.Therefore, the downsizing of the protection member is advantageous toenvironmental issues.

However, if a configuration in which a central portion of the guide railin a longitudinal direction is disconnected is produced in order todecrease sliding resistance caused when the process cartridge is movedalong the guide rail of the protection member, the following problem maybe caused. That is, when a configuration of a protection member having aU-shape like FIG. 2 of the present application is further applied interms of downsizing and space saving of the cartridge, the protectionmember has no bottom surface and thus falls, and the process cartridgemay not be able to be used.

SUMMARY OF THE INVENTION

It is desirable to provide a cartridge that can be suppressed fromfalling off a protection member at the time of insertion of thecartridge.

It is further desirable to provide a process cartridge detachablyattachable to an image forming apparatus having a configuration below.The process cartridge includes: a cartridge including an image bearingmember; a protection member detachably and attachably provided by beingslid to the cartridge, and adapted to cover the image bearing member; alock portion adapted to lock the protection member to be moved to thecartridge; an upstream-side rib and a downstream-side rib respectivelyprovided at an upstream side and a downstream side of the cartridge inan inserting direction into which the cartridge is inserted into theimage forming apparatus; a first support portion provided in theprotection member, and adapted to support the upstream-side rib when theprotection member is locked to the cartridge main body, to support theupstream-side rib in an area where the cartridge is inserted into apredetermined position of the image forming apparatus when the cartridgeis inserted into the image forming apparatus, and not to support theupstream-side rib in an area where the cartridge is further insertedfrom the predetermined position of the image forming apparatus; and asecond support portion provided in the protection member, and adapted tosupport the downstream-side rib when the protection member is locked tothe cartridge main body.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view illustrating a configuration of an imageforming apparatus according to an embodiment of the present invention.

FIG. 2A is a perspective view of a cartridge, as viewed from a side of arib, FIG. 2B is a perspective view of the cartridge, as viewed from aside of a guide, and FIG. 2C is a sectional view of the cartridge.

FIGS. 3A and 3B are perspective view of a protection member.

FIGS. 4A to 4C are perspective view of the protection member.

FIG. 5A is a perspective view of a state where the cartridge isprotected by the protection member, FIG. 5B is a sectional view of astate where the cartridge is protected by the protection member, asviewed from a direction of an arrow J2 of FIG. 5A, and FIG. 5C is asectional view of a state where the cartridge is protected by theprotection member, as viewed from a direction of an arrow J3 of FIG. 5A.

FIG. 6A is a sectional view of a vicinity of a lock member, as viewedfrom a direction of an arrow E of FIG. 5B, and FIG. 6B is a sectionalview of a vicinity of the lock member of when a base body and thecartridge are separated, as viewed from the direction of the arrow E ofFIG. 5B.

FIGS. 7A and 7B are perspective view illustrating a process in which thecartridge is attached to/detached from a device main body.

FIGS. 8A and 8B are perspective view illustrating a process in which thecartridge is attached to/detached from the device main body.

FIGS. 9A and 9B are perspective view illustrating a process in which thecartridge is attached to/detached from the device main body.

FIGS. 10A and 10B are perspective view illustrating the cartridge and acartridge rail.

FIGS. 11A and 11B are perspective view illustrating a configuration of aportion to be mounted, and FIG. 11B is a perspective view illustrating astate in which the cartridge presses down a lock cancellation member.

FIGS. 12A and 12B are diagrams illustrating an operation of the lockmember.

FIGS. 13A to 13C are diagrams illustrating an operation of the lockmember.

FIGS. 14A to 14C are diagrams illustrating an operation of the lockmember.

FIG. 15A is a sectional view illustrating the guide of the protectionmember and the rib of the cartridge, and FIGS. 15B and 15C areperspective views of a cartridge rail.

FIGS. 16A and 16B are sectional view illustrating a pressing member andthe cartridge.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, embodiments for implementing the present invention will beexemplarily described in detail with reference to the drawings. Notethat dimensions, materials, shapes, relative positions, and the like ofconfiguration components described in the embodiments are appropriatelychanged according to a configuration of a device to which the inventionis applied and various conditions. Therefore, it is not intended tolimit the scope of the invention to the embodiments unless otherwiseespecially stated.

FIG. 1 is a sectional view illustrating a configuration of an imageforming apparatus 1 according to an embodiment of the present invention.Here, examples of the image forming apparatus include anelectrophotography copying machine, an electrophotography printer (forexample, an LED printer or a laser beam printer), and anelectrophotography facsimile device.

The image forming apparatus 1 includes a device main body 1A. Imageforming portions 10 of respective colors of Y (yellow), M (magenta), C(cyan), and K (black) are arrange inside the device main body 1A. Theimage forming portion 10 includes a photosensitive drum 11. A chargingroller 12, a laser scanner 13, a development device 14, a cleaning blade15, and a primary transfer roller 17 are included around thephotosensitive drum 11. An intermediate transfer belt 61 is arrangedabove the photosensitive drum 11. The intermediate transfer belt 61 issuspended around a drive roller 62 and rollers 63 and 64.

A surface of the photosensitive drum 11 is uniformly changed by thecharging roller 12, and an electrostatic image is formed by the laserscanner 13 and is developed by the development device 14 with toner, sothat a toner image is formed. The primary transfer roller 17 transfersthe toner images on the surfaces of the four photosensitive drums 11 tothe intermediate transfer belt 61. A small amount of residual tonerremaining on the surfaces of the photosensitive drums 11 is removed bythe cleaning blade 15, and again stands by for the next image formation.A toner cartridge 19 is arranged above the intermediate transfer belt61, and supplies the toner to the development device 14.

Meanwhile, sheets P are fed to the cassette 20 one by one, and areconveyed to a pair of registration rollers 23. A tip of the sheet P isformed into a loop to follow a nip portion of the pair of registrationrollers 23, so that skew feeding is corrected. Following that, the pairof registration rollers 23 conveys the sheet P between the intermediatetransfer belt 61 and a secondary transfer outer roller 35 insynchronization with the toner image on the intermediate transfer belt61. The color toner image on the intermediate transfer belt 61 isapplied predetermine welding force and electrostatic load bias in a nipportion of the drive roller 62 and the secondary transfer outer roller35, which are arranged to face each other, thereby to be transferred tothe sheet P.

A small amount of residual toner remaining on the surface of theintermediate transfer belt 61 is removed and collected by a cleaningcartridge 70 having a cleaning blade 77, and again stands by for thenext image formation. The toner image transferred on the sheet P isfixed by a fixing device 40 by being heated and pressurized, and thesheet P is discharged onto a discharge tray 50 by a pair of dischargerollers 41.

(Drum Cartridge)

FIG. 2A is a perspective view of a cartridge main body 100, as viewedfrom a side of a rib 102. FIG. 2B is a perspective view of the cartridgemain body 100, as viewed from a side of a guide 103. FIG. 2C is asectional view of the cartridge main body 100. The cartridge main body100 is detachably attachable to the device main body 1A. The cartridgemain body 100 includes a housing 101.

The housing 101 includes and integrally supports the photosensitive drum11 as the image forming portion 10 as an “image forming unit”, thecharging roller 12, and the cleaning blade 15. The photosensitive drum11 and the charging roller 12 are rotatably supported with respect tothe housing 101. The charging roller 12 and the cleaning blade 15 aresupported in a state of being pressurized against the photosensitivedrum 11.

The photosensitive drum 11 is connected to a drive source (notillustrated) of the device main body 1A and is rotated. The chargingroller 12 is rotated, following the photosensitive drum 11, because thecharging roller 12 is pressurized against the photosensitive drum 11.The photosensitive drum 11, the charging roller 12, and the cleaningblade 15 become deteriorated when image formation is performed.Therefore, the cartridge main body 100 needs to be replaced according toa print amount.

Further, a guide 104 that guides a rotation phase of a lock member 230(lock portion) (see FIG. 3) provided in a protection member 200 isprovided in the cartridge main body 100. A detailed operation regardinglock will be described in a procedure of replacing the cartridge mainbody 100.

Therefore, the cartridge main body 100 can be inserted into a depthdirection of the device main body 1A and can be taken out to a frontdirection. A lock cancellation member 16 that is operated when thecartridge main body 100 is extracted from the device main body 1A isprovided in the cartridge main body 100 to partially protrude from thecartridge main body 100.

The rib 102 guided to a guide 212 of a base body 210 of the protectionmember 200 at the time of insertion, and the guide 103 for guiding a rib213 of the base body 210 of the protection member 200 are provided inthe cartridge main body 100. The ribs 102 are a pair of ribs, and arerespectively provided in the cartridge main body 100 at an upstream sideand a downstream side in an inserting direction of the cartridge mainbody 100. The ribs 102, the guide 103, and the guide 104 extend in adirection along an attaching/detecting direction M of the cartridge mainbody 100. Further, the image forming portion 10 is guided to the devicemain body 1A by the ribs 102 and the guide 103.

Further, the guide 104 that guides the rotation phase of the lock member230 of the protection member 200 is provided in the cartridge main body100. An operation of the lock cancellation member 16 related to anoperation at the time of insertion/extraction of the cartridge main body100 and a detailed operation related to the lock member 230 will bedescribed in the procedure of replacing the cartridge main body 100.

(Drum Cartridge Protection Member)

FIGS. 3A and 3B and FIG. 4A are perspective views of the protectionmember 200. The protection member 200 protects the image forming portion10. The protection member 200 is detachably and attachably provided tothe cartridge main body 100, has one end open in a cross sectionperpendicular to the attaching/detaching direction, and covers at leasta part of a surface of the cartridge main body 100 except a lowersurface portion of the cartridge main body 100.

The protection member 200 includes the base body 210 having anapproximately U-shape in the cross section perpendicular to theattaching/detaching direction, a pushing-out member 220 independentlyattached to the base body 210, and the lock member 230. The protectionmember 200 includes an insertion portion 211 inserted into the devicemain body 1A. The protection member 200 includes the guide 212 and therib 213 that support the cartridge main body 100 and guide the cartridgemain body 100 when the cartridge main body 100 is inserted into thedevice main body 1A, inside the base body 210. The rib 102 of thecartridge main body 100 passes through the guide 212.

The guide 212 includes guides 212A and 212B as “a pair of supportportions”. The guide 212 is provided in the protection member 200, andsupports the pair of ribs 102 when the protection member 200 is lockedto the cartridge main body 100.

Further, the pushing-out member 220 is independently attached to thebase body 210. As illustrated in FIG. 4B, the pushing-out member 220includes an operation portion 221, a pushing-out surface 222, and anengaging portion 223. At the time of replacement of the cartridge mainbody 100, an operator moves the operation portion 221 in the insertingdirection of the cartridge main body 100, thereby to move the cartridgemain body 100 while the pushing-out surface 222 is in contact with thecartridge main body 100. The engaging portion 223 will be described indetail in the procedure of replacing the cartridge main body 100described below.

Further, the lock member 230 is independently attached to the base body210. The lock member 230 includes a cartridge lock portion 231 forlocking the cartridge main body 100 and the base body 210 and a coverlock portion 232 for locking the protection member 200 and the devicemain body 1A. As illustrated in FIG. 4C, the lock member 230 isrotatably held to the base body 210 in a direction of an arrow A1.

(Protection State of Drum Cartridge)

FIG. 5A is a perspective view of a state in which the cartridge mainbody 100 is protected by the protection member 200. FIG. 5B is asectional view of a state in which the cartridge main body 100 isprotected by the protection member 200, as viewed from a direction of anarrow J2 of FIG. 5A. FIG. 5C is a sectional view of a state in which thecartridge main body 100 is protected by the protection member 200, asviewed from a direction of an arrow J3 of FIG. 5A. FIG. 6A is asectional view of a vicinity of the lock member 230, as viewed from adirection of an arrow E of FIG. 5B. Here, a cartridge 1000 includes thecartridge main body 100 and the protection member 200.

The protection member 200 covers and protects the cartridge main body100, thereby to protect the photosensitive drum 11, the charging roller12, and the cleaning blade 15 housed in the image forming portion 10.The guide 212 of the protection member 200 and the rib 102 of thecartridge main body 100 are engaged with each other. The rib 213 of theprotection member 200 and the guide 103 of the cartridge main body 100are engaged with each other.

When the cartridge main body 100 is protected by the protection member200, the lock member 230 exists in the position illustrated in FIGS. 5Band 6A, and the cartridge lock portion 231 of the lock member 230 isengaged with a recessed portion 100X (lock portion) of the cartridgemain body 100. Therefore, the lock member 230 locks the cartridge mainbody 100 not to be slid in a direction of an arrow B relative to theprotection member 200. At the same time, the protection member 200 issuppressed to be opened in a direction of an arrow C by the cartridgelock portion 231 of the lock member 230 and an opening-prevention rib105 of the cartridge main body 100.

When the base body 210 has an approximately U-shape, as illustrated inFIG. 3, the shape is vulnerable to deformation in the direction of thearrow C. If the base body 210 is deformed in the direction of the arrowC, the lock member 230 attached to the base body 210 is also moved inthe direction of the arrow C, following the deformation of the base body210.

FIG. 6B is a sectional view of a vicinity of the lock member 230 of whenthe base body 210 and the cartridge main body 100 are separated, asviewed from the direction of the arrow E of FIG. 5B. In the positionwhere the lock member 230 illustrated in FIG. 6B has moved in thedirection of the arrow C by a fixed amount, the cartridge lock portion231 of the lock member 230 cannot regulate the movement of the cartridgemain body 100 in the direction of the arrow B. As a result, thecartridge main body 100 can be moved in the direction of the arrow B (adirection of being dropped out from the protection member 200), andfalls off the protection member 200.

The opening-prevention rib 105 and the cartridge lock portion 231 areengaged with each other, so that the cartridge main body 100 can beprevented from falling off the protection member 200 due to thedeformation of the base body 210.

(Procedure of Replacing Drum Cartridge)

Next, a procedure of replacing a drum cartridge (a cartridge main body100C of cyan) using the protection member 200 of the present inventionwill be described. The procedure of replacing the cartridge main body100 will be described by reference to FIGS. 7 to 16. The device mainbody 1A provides a sign of replacement of the cartridge main body 100Cof cyan. A user opens a front cover 400 (FIG. 7A). The front cover 400is provided in front of the device main body 1A, and is turned toopen/close. When releasing the front cover 400, the user can access thecartridge main body 100 of the device main body 1A.

The lock of the cartridge main body 100C is cancelled, and the cartridgemain body 100C is pulled out (FIG. 7B). As illustrated in FIG. 10, thecartridge main body 100C is locked to the front of the device main body1A (a direction of an arrow F) not to be dropped out with a hookingprojection 411 provided in the cartridge rail 410.

As illustrated in FIG. 11B, when the lock cancellation member 16provided in the cartridge main body 100C is pressed down in a directionof an arrow D, and the hooking projection 411 formed in a cartridge rail410 is pressed down to cancel the lock of the cartridge main body 100C,the cartridge main body 100C can be pulled out of the device main body1A in the direction of the arrow F. After the cartridge main body 100Cis pulled out, the cartridge main body 100C has already been used, andthus protection after pulled out may be more roughly performed than atthe time of insertion because it is not a problem even if an exposureportion is damaged. The cartridge main body 100C after pulled out iscollected by a service person or the like.

An insertion portion 201 of the protection member 200 is inserted into aportion to be inserted 301 of the device main body 1A in a state wherethe cartridge main body 100C is protected by the protection member 200(FIGS. 8A and 11A).

FIG. 12A is a side view of the protection member 200. As illustrated inFIG. 12A, the insertion portion 201 of the protection member 200 and theportion to be inserted 301 of the device main body 1A have smallrattling in an engagement width X. Therefore, when an insertion amount ybecomes large to some extent, the protection member 200 does not falleven if the hand of the user is separated from the protection member200.

When the insertion portion 201 of the protection member 200 is insertedand pushed into the portion to be inserted 301 of the device main body1A, the cover lock portion 232 of the lock member 230 of the protectionmember 200 comes in contact with the cancellation lock rib 302 of thedevice main body 1A, and the lock member 230 is rotated in the directionof the arrow A1. The protection member 200 is further pushed, the coverlock portion 232 enters more inside of the device main body 1A than thecancellation lock rib 302 (FIGS. 12A to 13A).

At the same time, the lock member 230 is rotated in the direction of thearrow A1 and is transferred to the state of FIG. 14A, as illustrated inFIG. 12A→FIG. 12B→FIG. 13A. Then, the lock is cancelled due to theengagement of the cartridge lock portion 231 with the recessed portion100X of the cartridge main body 100C between the protection member 200and the cartridge main body 100C. The cartridge main body 100C can thenbe slid in the direction of the arrow B.

When the pushing-out member 220 of the protection member 200 is operatedin the direction of the arrow B, the cartridge main body 100C is pushedout by the pushing-out surface 222 of the pushing-out member, and onlythe cartridge main body 100C is inserted into the device main body 1Awhile the protection member 200 remains on site (FIGS. 8A and 8B).

At this time, the rib 102 of the cartridge main body 100C and the guide212 of the base body 210, the guide 103 of the cartridge main body 100and the rib 213 of the base body 210 are respectively engaged with eachother, so that the cartridge main body 100C is protected by theprotection member 200. When the cartridge main body 100C is moved in thedirection of the arrow B, the cartridge main body 100C passes on the rib102 and the guide 212. At this time, if the guide 212 exists in theentire inserting direction (R1+R2+R3 of FIG. 15A), sliding resistance atthe time of insertion of the cartridge main body 100 is always appliedduring the insertion, and operability is deteriorated.

Further, if a guide exists near the center in the longitudinal direction(R2 of FIG. 15A), the guide and the surface of the photosensitive drum11 are in contact with each other when the base body 210 is deformed,and the photosensitive drum 11 may be damaged. Therefore, limiting anarea where the guide 212 exists (R1 and R3 of FIG. 15A) is effective foroperability and safety of replacement of the cartridge main body 100.

A minimum area necessary for the guide 212 is a position where the guide212 supports the rib 102 in a state where the cartridge main body 100Cis protected by the protection member 200. In a protection state,movement of the cartridge main body 100C in the direction of the arrow Bis regulated by the lock member 230. Therefore, even if the guide 212 isprovided to be limited to the area where the guide 212 supports the rib102, the cartridge main body 100C does not fall off the protectionmember 200 at the time of distribution of the cartridge main body 100.Therefore, the guide 212 is formed such that a section in the middle ofthe attaching/detaching direction of the cartridge main body 100 isdisconnected in the position where the protection member 200 can supportthe rib 102.

However, if the area where the guide 212 is provided is too narrow, thecartridge main body 100C may fall off the protection member 200 in astate where the insertion amount of the cartridge main body 100C to thedevice main body 1A is small. Meanwhile, if the cartridge main body 100Cis inserted into the device main body 1A by a fixed amount, thecartridge main body 100C can be independent of the device main body 1A.Therefore, the guide 212 for supporting the rib 102 is provided up to aposition where the cartridge main body 100C can be independent of thedevice main body 1A (R1 of FIG. 15A).

That is, a guide 212A as a taking-out direction-side portion, as a“portion at a side in a taking-out direction of the cartridge main body100” of the guide 212 is not disconnected up to a distance where thecartridge main body 100 becomes independent of the device main body 1A.In doing so, the cartridge main body 100C can be prevented from fallingoff the device main body at the time of replacement. Note that the guide212B arranged at the downstream side in the inserting direction of thecartridge has a guiding function in the present embodiment. However, theguide 212B may not necessarily have the guiding function as long as theguide 212B can support the rib 102 at least before insertion of thecartridge.

The guide 212A as an “upstream support portion” arranged at an upstreamside in the inserting direction of the cartridge main body 100, of thepair of guides 212, can guide the rib 102 when the cartridge main body100 is inserted into the device main body 1A, and terminates the guideof the rib 102 after allowing the cartridge main body 100 to be insertedup to the position where the cartridge main body 100 becomes independentof the device main body 1A. The guide 212A terminates the guide of therib 102 before the cartridge main body 100 is half or more inserted intothe device main body 1A.

In the area where the guide 212 does not exist (R2 in FIG. 15A), thepushing-out member 220 abuts on the cartridge main body 100 at aposition below the cancellation member of a protruding portion 300 on afront surface of the cartridge main body 100C (see FIG. 15A). Thepushing-out member 220 includes the pushing-out surface 222 that comesin contact with the cartridge main body 100, and a part of the cartridgemain body 100 exists at an upper side than an upper surface of thepushing-out member 220 in the position where the pushing-out surface 222is in contact with the cartridge main body 100. Therefore, thepushing-out member 220 can support the cartridge main body 100 not tofall off the protection member 200. Accordingly, falling of thecartridge main body 100C during insertion can be prevented by the guide212 and the pushing-out member 220.

The pushing-out member 220 is a member movably held to the protectionmember 200, and can push out the cartridge main body 100. Thepushing-out member 220 can be moved in association with the movement ofthe cartridge main body 100 such that a part of the cartridge main body100 is positioned above the pushing-out member 220 in the verticaldirection, until the cartridge main body 100 is guided to the mountposition of the device main body 1A. The pushing-out member 220 includesthe engaging portion 223 that is to be engaged with the cartridge mainbody 100, and the engaging portion 223 is released from the cartridgemain body 100 in a state where the cartridge main body 100 is mounted tothe device main body 1A.

However, if an operator directly pushes out the cartridge main body 100Cin the direction of the arrow B without using the pushing-out member220, the falling of the cartridge main body 100 in the area where noguide 212 exists (R2 in FIG. 15A) cannot be prevented.

At this time, as illustrated in FIG. 16B, the engaging portion 223 ofthe pushing-out member 220 is engaged with the lock cancellation member16 of the cartridge main body 100, so that the pushing-out member 220 ismoved in the direction of the arrow B, following the movement of thecartridge main body 100C, and the falling in the area where no guide 212exists can be prevented. With the above configuration, even if theoperator performs a wrong operation, replacement work of the cartridgemain body 100 can be safely performed.

Further, a detailed operation of the lock member 230 at this time willbe described. The cartridge lock portion 231 of the lock member 230 isguided by the guide 104 of the cartridge main body 100C in the directionof the arrow A2, as illustrated in FIG. 14B.

When the lock member 230 is rotated in the direction of the arrow A2, asillustrated in FIG. 13B, the cover lock portion 232 goes around behindthe cancellation lock rib 302 of the device main body 1A.

In this state, when the protection member 200 is pulled out of thedevice main body 1A, the cartridge lock portion 231 of the lock member230 is guided by the guide 103 of the cartridge main body 100C.Therefore, the lock member 230 cannot be rotated, and the cover lockportion 233 is caught by the cancellation lock rib 302 of the devicemain body 1A, and the protection member 200 cannot be pulled out.

If the protection member 200 can be pulled out in a state where thecartridge main body 100C is slightly pushed out, and the protectionmember 200 is pulled out, the cartridge main body 100C is in an unstablestate to the protection member 200 and to the device main body 1A, andthus falls. This can be avoided by providing the lock mechanism of theprotection member 200.

Further, the lock of the device main body 1A and the protection member200 is performed in conjunction with normal work of pushing out of thecartridge main body 100C. Therefore, it is not necessary to increase anoperation to lock the device main body 1A and the protection member 200.

When the cartridge main body 100C is pushed deep, as illustrated in FIG.8B, an inclined portion 412 (see FIGS. 15B and 15C) is provided in thecartridge rail 410 at the downstream side in the inserting direction ofthe cartridge main body 100, and thus the cartridge main body 100C canbe raised in a height direction along the inclined portion 412 at theend of the insertion. With this displacement, the engaging portion 223of the pushing-out member 220 and the cartridge main body 100C aredisengaged, as illustrated in FIG. 16B. Therefore, the engaging portion223 is released from the cartridge main body 100 in the state where thecartridge main body 100 is mounted to the device main body 1A.

Further, when the cartridge main body 100C is pushed deep, the cartridgelock portion 231 of the lock member 230 is guided by the guide 104, andthe lock member 230 is rotated in the direction of the arrow A1 again,as illustrated in FIG. 13A. The cover lock portion 232 does not overlapwith the cancellation lock rib 302 in the pulling out direction.Therefore, the protection member 200 can be removable state (FIG. 13C).The lock cancellation of the device main body 1A and the protectionmember 200 is also performed in conjunction with a normal operation,similarly to the lock. Therefore, it is not necessary to increase anoperation.

Further, when the lock is cancelled, the cartridge main body 100C isindependent of the device main body 1A because the device main body 1Aand the protection member 200 are engaged in a state where theengagement rattling is small. Therefore, the protection member 200cannot fall after completion of the insertion of the cartridge main body100C.

The protection member 200 is removed (FIG. 9A). The cover lock portion232 comes free from the cancellation lock rib 302, as illustrated inFIG. 12B. Therefore, the protection member 200 can be removed from thedevice main body 1A. The front cover 400 is closed (see FIG. 9B)(completion).

In the present embodiment, an example of replacing the cyan cartridgemain body 100C has been described. However, replacement is similarlyperformed for other cartridge main bodies 100.

Further, in the present embodiment, an example of the cartridge mainbody 100 has been described. However, an embodiment is not limited tothe example. Anything can be employed as long as the one includes animage forming unit such as a charging cartridge having only a chargingfunction, a cleaner cartridge having only a function of a cleaner, atransfer cartridge having a transfer function, or a fixing cartridgehaving a fixing function.

An example of moving the cartridge main body 100, using the inclinedportion 412 provided in the cartridge main body 100 of the cartridgerail 410 attached to the device main body 1A so that the engagingportion 223 of the pushing-out member 220 and the cartridge main body100 are disengaged in the process of insertion has been described. Notethat the engagement may be disengaged by movement of the cartridge mainbody 100 by the guide 212 of the protection member 200, or may bedisengaged by movement of the pushing-out member.

As described above, the cartridge main body 100 is positioned to thedevice main body 1A in the state where the cartridge main body 100 isprotected by the protection member 200, and then the cartridge main body100 is inserted into the device main body 1A. In doing so, the cartridgemain body 100 can be inserted into the device main body 1A withoutdamaging the photosensitive drum 11 as the image forming portion 10, thecharging roller 12, and the cleaning blade 15.

According to the present invention, when the cartridge main body 100 isinserted into the device main body 1A, falling of the cartridge mainbody 100 is prevented by the guide 212 of the protection member 200until the cartridge main body 100 is inserted up to the position wherethe cartridge main body 100 can be independent of the device main body1A. Falling of the cartridge main body 100 is prevented by thepushing-out member 220 while the guide 212 is disconnected, so thatfalling of the cartridge main body during insertion can be prevented.

Further, by limiting the area where the guide 212 is provided, thesliding resistance at the time of insertion of the cartridge main body100 can be reduced, and the cartridge main body 100 can be replaced withlight operation force. Further, the guide 212 is not provided in thecentral portion in the longitudinal direction, which is easily deformed.Therefore, the contact between the guide 212 and the surface of thephotosensitive drum 11 can be prevented.

Further, by engaging the pushing-out member 220 and the cartridge mainbody 100, falling of the pushing-out member 220 can be prevented even ifthe operator wrongly pushes out the cartridge main body 100 in a directmanner.

As a result, downsizing of the protection member 200 can be realizedwhile operability and safety of replacement work of the cartridge mainbody 100 can be maintained.

According to the present invention, in the configuration in which theprotection member protects the cartridge and the center of the supportportion provided in the protection member is disconnected, the cartridgecan be prevented from falling off the protection member at the time ofinsertion of the cartridge.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2015-011873, filed Jan. 24, 2015, which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. A cartridge unit comprising: a cartridgeconfigured to be attached to an image forming apparatus main body havinga cartridge guide for guiding movement of the cartridge, the cartridgecomprising: a photosensitive drum; and a housing configured to supportthe photosensitive drum rotatably, wherein the cartridge is configuredto be attached to the image forming apparatus main body by slidingmovement in a direction of a rotary axis of the photosensitive drum; anda protection cover configured to protect a photosensitive surface of thephotosensitive drum and configured to support the housing before beingattached to the image forming apparatus main body, the protection cover(i) being temporally attached to the image forming apparatus main bodyto guide attachment of the cartridge in a process of attaching thecartridge to the image forming apparatus main body, and (ii) beingdetached from the image forming apparatus body after supporting theattachment of the cartridge, the protection cover comprising: a frameincluding a protecting portion that covers the photosensitive surface,with a lower portion of the frame in a vertical direction being open ina state in which the protection cover is attached to the image formingapparatus main body; a first supporting portion and a second supportingportion projecting from a face of the frame and facing a side of thecartridge so as to support the cartridge before the cartridge isattached to the image forming apparatus main body, the first supportingportion and the second supporting portion being disposed at differentpositions in the direction of the rotary axis; and a pushing-out portiondisposed on the frame so that the pushing-out portion moves by slidingin the direction of the rotary axis so as to push the cartridge to movetoward the image forming apparatus main body during the attachingprocess, with the pushing-out portion supporting the cartridge, whereinthe cartridge is removed from the support by the first supportingportion and the second supporting portion in a state in which thepushing-out portion slides to move the cartridge, with the cartridgethereby being attached to the image forming apparatus main body and thecartridge being supported by the pushing-out portion and the cartridgeguide.
 2. The cartridge unit according to claim 1, wherein the frame hasU-shape in a cross-section in a vertical direction through the rotaryaxis.
 3. The cartridge unit according to claim 1, further comprising alock mechanism configured to lock the protection cover to the imageforming apparatus main body, wherein the lock mechanism comprises a lockportion configured to lock the protection cover to the image formingapparatus main body when the cartridge is inserted by the pushing-outportion.
 4. The cartridge unit according to claim 1, wherein thepushing-out portion is configured to push the cartridge at an upstreamside in a sliding direction of the cartridge during the attachingprocess.
 5. A cartridge unit comprising: a cartridge configured to beattached to an image forming apparatus main body having a cartridgeguide for guiding movement of the cartridge, the cartridge comprising: aphotosensitive drum; a housing configured to support the photosensitivedrum rotatably, wherein the cartridge is configured to be attached tothe image forming apparatus main body by sliding movement in a directionof a rotary axis of the photosensitive drum; and a protection coverconfigured to protect a photosensitive surface of the photosensitivedrum and configured to support the housing before being attached to theimage forming apparatus main body, the protection cover (i) beingtemporally attached to the image forming apparatus main body to guideattachment of the cartridge in a process of attaching the cartridge tothe image forming apparatus main body, and (ii) being detached from theimage forming apparatus body after supporting the attachment of thecartridge, the protection cover comprising: a frame including aprotecting portion that covers the photosensitive surface, with a lowerportion of the frame in a vertical direction being open in a state inwhich, the protection cover is attached to the image forming apparatusmain body; a first supporting portion, a second supporting portion, athird supporting portion, and a fourth supporting portion projectingfrom a face of the frame and facing to a side of the cartridge so as tosupport the cartridge before the cartridge is attached to the imageforming apparatus main body, the first supporting portion and the secondsupporting portion being disposed at different positions in thedirection of the rotary axis, the third supporting portion and thefourth supporting portion being disposed at different positions in thedirection of the rotary axis, and the first supporting portion and thesecond supporting portion being disposed at an opposite side of thecartridge from the third supporting portion and the fourth supportingportion in a horizontal direction; and a pushing-out portion disposed onthe frame so that the pushing-out portion moves by sliding in thedirection of the rotary axis so as to push the cartridge to move towardthe image forming apparatus main body during the attaching process, withthe pushing-out portion supporting the cartridge, wherein the cartridgeis removed from support by the first supporting portion, the secondsupporting portion, third supporting portion, and the fourth supportingportion in a state in which the pushing-out portion slides to move thecartridge, with the cartridge thereby being attached to the imageforming apparatus main body and the cartridge being supported by thepushing-out portion and the cartridge guide.
 6. The cartridge unitaccording to claim 5, wherein the frame has U-shape in a cross-sectionin a vertical direction through the rotary axis.
 7. The cartridge unitaccording to claim 5, further comprising a lock mechanism configured tolock the protection cover to the image forming apparatus main body,wherein the lock mechanism comprises a lock portion configured to lockthe protection cover to the image forming apparatus main body when thecartridge is inserted by the pushing-out portion.
 8. The cartridge unitaccording to claim 5, wherein the pushing-out portion is configured topush the cartridge at an upstream side in a sliding direction of thecartridge during the attaching process.